Structural health monitoring (SHM) is a process of identifying damage in structures and components. Generally speaking, damage can be characterized as a change in the material or geometric properties of the structure such as weakening or physical distortion. Typically, SHM systems monitor and measure structural properties over time and compare the current results to either baseline measurements or historical measurements to determine the current health of the structure. For example, sensors in bridges can monitor the properties of the bridge components over time to identify when the bridge has become unsafe due to deterioration or an event like an earthquake.
Similar SHM systems have been employed in aircraft to monitor the airframe and various aircraft structures to help identify structural issues with aircraft components before they fail. One such technique is to use an ultrasonic guided wave (UGW) system to detect damage to various mechanical structures and components due to impacts, corrosion, and the like. Generally speaking, the UGW system transmits a signal between two points on the component and determines the health of the component based on how the signal has changed relative to a reference value. However, the signals transmitted through the component are not just impacted by the presence of structural damage, but environmental factors as well. Component temperature, loading, or age can all negatively impact the reliability of the SHM system by increasing the number of false positives or, in a worse case, masking real structural damage.
Accordingly, it is desirable to provide a system and method for detecting and identifying structural damage in a component that minimizes the impact of environmental factors on the SHM reading. Furthermore, other desirable features and characteristics of the exemplary embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.